1. Field of the Invention
The present invention relates generally to the art of cutting food products, and more specifically to a device for cutting vegetables, such as potatoes, into desired shapes. Still more specifically, the present invention, in its most preferred form, relates to a system for cutting helical strips of potatoes and includes a pair of endless belts carrying contoured paddles for aligning and feeding potatoes through a rotating cutting mechanism.
2. Description of the Prior Art
Many devices have been described in the prior art for cutting and slicing vegetables, including potatoes. Many of the devices described in the patent literature are designed for use at home or for the handling of individual food products. Simple examples of such systems would be found in most households, e.g. rotary food processors, vegetable slicers, etc.
The commercial cutting of potatoes into variously shaped pieces has also been known for a number of years. Frozen potatoes can be purchased in grocery stores in a variety of shapes, including the common shoe string shape (generally square in cross-section and having a length of 3-4 inches or longer), crinkle-cut (which have a corrugated appearance), and in recent years, helical strips of potatoes which are of the type sold by the assignee of the present invention under the trademark CURLEY Q.RTM.. Many other shapes of potatoes are available in restaurants, and the variety of shapes has risen dramatically in recent years. Potatoes are now manufactured for distribution with skin on or with skin off and are prepared for reconstitution by deep frying, baking, microwave heating, etc.
The evolution of the helical potato is a phenomenon of the middle to late 80's. Somewhat similarly shaped products were known prior to that time and were prepared using hand crank machines such as those encountered at county fairs and in small restaurants. The early cutters for making helical strips typically had a system for impaling the potato on a rotating, screw driven holder and for rotating it into a fixed knife to produce helical strips. The product was typically uneven in appearance, and the process was also slow. Moreover, the process typically resulted in inefficient use of the potato, as the butt ends of the potato were not included in the final product and were discarded or were used for other purposes.
It was not until the assignee of the present invention introduced the CURLEY Q.RTM. potatoes in 1983 that the cut variety became popular on a national basis, especially in institutional food outlets such as fast food restaurants, hotels, schools and the like. The reason for the increase in popularity was the improved product quality and appearance and the ability to commercially manufacture the product using the cutting device described in U.S. Pat. No. 4,644,838, issued Feb. 24, 1987 to Sampson, et al. and entitled "Apparatus For Helical Cutting Of Potatoes". In the device shown in this patent, various conveyors bring potatoes to a plurality of tubes. A potato is deposited in each tube and held therein against rotation by a plurality of spring loaded, generally triangularly shaped fingers. A knife, which includes a number of upstanding scoring blades, and a radially extending slicing blade is located beneath the tube and is designed to be rotated during the cutting operation. The patent further describes a plunger system for exerting downwardly extending forces on the potato held in the tube to push the potato through the slicing knife, resulting in a plurality of helical strips of varying diameter, depending on the distance from the axis of the tube.
In the preferred embodiment of the Sampson, et al. patent, the bottom of the plunger includes recesses to receive the upstanding scoring blades, so that the entire potato can be cut using the process. This feature eliminates prior difficulties with the waste resulting from butt ends. The knife itself is rotated by a motor and a belt, and a stationary tube located on the downstream side of the knife receives the product. After being cut, separation of the various coils takes place to improve product appearance. Initially, such separation was accomplished by hand. Later developments have lead to mechanical coil separators for this part of the process. Following cutting, downstream processing includes par-frying, freezing and packaging. The CURLEY Q.RTM. fries have also been coated with batter and flavor ingredients to result in a family of products having different taste and appearance characteristics.
Since the introduction of this product by the assignee of the present invention, numerous other frozen potato manufacturers have introduced similarly shaped products, some using different cutting technologies. Moreover, the assignee of the present invention has itself developed improvements, such as a "cutting assembly" described in U.S. patent application Ser. No. 07/682,653, filed in the name of Foster on Apr. 9, 1991. In this application, a tiered blade is used instead of the blade described in the Sampson, et al. patent. The blade is positioned to form concentric longitudinal cuts in the potato, such that helical strips are produced in an efficient and reproducible manner.
Other patents have issued to competitors of the assignee on cutting knives and on production devices, such as the systems described in U.S. Pat. No. 4,926,726, issued May 22, 1990 to Julian and entitled "Food Processing Apparatus" and U.S. Pat. No. 4,979,418, issued Dec. 25, 1990 to Covert, et al. and entitled "Food Processing Apparatus". In both patents, a rotating cutting knife is used to produce helical strips from potatoes forced through the knife using an elongate feed system including conveyors and spring biased paddle and spike members. The feed device is described as being very similar to the SC-120 Corn Cutter marketed by FMC Corporation to feed corn cob to a cutting assembly, which machine is described in detail in U.S. Pat. No. 2,787,273. The feed conveyor includes U-shaped areas on metal plates for centering the potato, dogs to maintain product alignment and a spring loaded plate floating on top of the potatoes as they pass along the line. As the potatoes enter the area adjacent the rotating cutting knife, they pass through a series of parallel shafts extending across the path of travel, the first two shaft pairs including a plurality of paddles which urge the potatoes forwardly toward the knife, and the last pair of shafts including a plurality of spikes which grasp and penetrate the potato as it is being pushed through the cutting knife. Each pair of shafts, one above and one below the feed path, is spring biased to compensate for different sized products. The device can operate continuously, with one potato following another through the system.
Another potato cutting system is described in U.S. Pat. No. 5,010,796 issued Apr. 30, 1991 to Mendenhall for "Helical Split Ring French Fry And Method For Making The Same" and concerns the preparation of helical, split-ring food products. Mendenhall employs the same general type of cutting knife used in the Samson et al. patent system, but the potato product is slotted before it reaches the knife so that, instead of coils, rings are produced. The conveyor system in Mendenhall includes a V-shaped lower portion, which is open at its bottom to permit the slotting blade to cut the potatoes, and spring biased rollers on the top to urge the potatoes toward the cutting knife. In one embodiment, the rollers are replaced by a belt which is generally planar and which is urged into contact with the potatoes by a plurality of spring biased rollers.
Water gun systems have also been known for some time in the potato processing field, i.e. systems which use a tube to align potatoes and water pressure to push the potatoes through the tube at increasing velocity and through knives of various types. Typically, such devices have been used for making straight cut potatoes, wherein fixed, crossed blades are mounted at the outlet of the water gun, and the potatoes are merely forced therethrough at high speeds.
One attempted use of a water-feed system for the preparation of helical cut french fries is described in U.S. Pat. No. 5,042,342, issued Aug. 27, 1991 to Julian for "Food Processing Apparatus". An embodiment disclosed in this application shows a tubular, elastic, tapered feed tube for feeding potatoes under the force of water pressure through a rotating cutting knife to form helical potato strips. According to the application, the elastomeric member expands once the potato reaches the tapered end, thus decreasing the velocity of the potato, but increasing the water pressure to the range of 15-25 psi. The applicant indicates that the potato is forced evenly and gently onto a central alignment tube of the knife and that the alignment tube further serves to decelerate the potato before the slicing blades cut the potato into helical strips. The specification also indicates that no external mechanical devices touch the potato, thus eliminating any damage to the outside of the potato.
While various systems have been proposed, it would represent a significant advance in this art to provide a feed system in which potatoes would be forced through a cutting head to form cut product at a consistent velocity and on a continuous basis, without the need to raise and lower a plunger between each product cutting step. It would also be desirable for some cut configurations and in some manufacturing environments to use a mechanical feed system, as opposed to water-feed systems. While it is desirable to minimize damage to the exterior of the potato, exterior damage is more likely to occur in the feed systems described in the Julian and Covert, et al. patents due to the nature of the paddles and the spikes used to drive the potato through the cutting knife. A system which mechanically drives potatoes, one following the other, into a cutting knife to produce high quality product, at increased speeds and with minimal mechanical forces being exerted on the skin of the potato would represent a very substantial advance in this art.